This application relates to a method and system for determining when a sensor is in need of calibration.
Sensors are utilized in any number of applications and monitor conditions within an environment.
As an example, chemical sensors may be placed in an occupied area and utilized to identify the presence of undesirable chemicals in the air. Such sensors respond to the presence of a particular substance and send a warning signal.
There may be a number of sensors in an area. Sensors typically require calibration periodically. In general, a time period between calibrations has been selected to be conservative.
Thus, the sensors tend to be calibrated too frequently, and before they need calibration. In an environment with a large number of sensors, this can be quite time-consuming and costly.
It has been proposed to determine the quality of a sensor's condition with an active system. Such an active system would expose a sensor on a controlled basis to the occurrence that it is intended to sense. The response to that exposure is then monitored. If the response is not as predicted, then an indication can be made that the sensor is in need of calibration.
However, such an active system is relatively complicated. This is especially true when there are a large number of sensors in a particular environment.